Dwyane Wade scored 26 points in Miami’s home opener, James had 15 points and seven assists and the Heat scored the first 14 points of the second half to turn a close game into a surprisingly one-sided 96-70 victory over the Magic.

“They came out, they threw an uppercut, and as a team we kind of went down,” Magic center Dwight Howard said.

Oh, this was a knockout, all right. The Heat had lost to Orlando 15 times in the last 20 meetings. Of course, all those were before Wade, James and Chris Bosh teamed up in Miami.

They preach defense in Miami, and this is why: The Heat held Orlando to its lowest point total since Dec. 2, 2005, and the 26-point margin matched Miami’s biggest ever against the Magic. The 30.4 percent shooting effort was Orlando’s worst since Nov. 3, 2003 — a span of 573 regular-season games.

“The guys now can’t go back on this,” Heat coach Erik Spoelstra said. “They’ve shown me what we’re capable of defensively and I will hold them to this standard now in terms of the effort. The effort was great.”

When the Heat acquired James this summer, Magic president of basketball operations Otis Smith uttered a now-infamous-in-Miami line: “I was surprised that he went. I thought he was, I guess, more of a competitor.”

They competed, all right, from start to finish.

“We heard everything Orlando had to say about us in the offseason,” James said. “It’s not like it’s satisfying. I’m not relieved, because it’s a long season. But they know we’re here for the long haul. We know they’re going to be there also, but this is a different Miami Heat team. There’s only so many words to be said. At this point, the ball has to be thrown up now.”

It didn’t take long for the trio to provide their first highlight: Bosh grabbed the ball at one end, passed toward midcourt to James, who took one dribble and found Wade for an alley-oop dunk to help Miami take an early 22-13 lead.

“Off to the races,” Bosh said.

They were just getting started.

Howard scored all 19 of his points in the first half for Orlando, then fouled out midway through the fourth quarter. Reserve Ryan Anderson scored 12 for the Magic, who got 10 from Jameer Nelson.

Miami’s starters — with no points from Joel Anthony — outscored Orlando’s first five 59-37.

“Overall, I thought it was just a terrible offensive execution,” said Magic forward Rashard Lewis, who was 0 for 9 from the floor.

The first half was fairly back-and-forth with eight lead changes and seven ties, neither team going up by more than nine.

That changed quickly coming out of intermission.

James hit a 3-pointer to open the second half, Wade connected on two more 3s within a 51-second span, and suddenly Miami’s lead was 60-45. Orlando coach Stan Van Gundy called timeout, and that didn’t change anything — James’ jumper about a minute later pushed the lead to 20.

And that, mind you, was against an Orlando team that cruised to a 29-point win over Washington on Thursday night. For a team with no shortage of offensive options, the Magic were icy cold against the Heat.

“It was really exciting — I mean, really exciting,” Bosh said. “The fans of Miami have been anticipating this game for a really long time, ever since July.”

Vince Carter played just 13 minutes, banging his head and hip on the floor while jostling for a rebound in the second quarter and finishing with four points. Orlando’s starting forwards — Lewis and former Heat starter Quentin Richardson — combined for four points and missed all 14 of their field-goal tries. J.J. Redick left for a few minutes in the first half after drawing a charge against James with the right side of his face, which was cut and puffy. Redick needed seven stitches.

Van Gundy wanted no part of the hyperbole surrounding Magic-Heat I — at least for this season — before the game, and certainly didn’t want to embrace it afterward.

“Their defense was very good, but I think when the defense is good, that’s when our passing problems become evident,” Van Gundy said. “I thought our passing was horrendous tonight.”

It was over after the third quarter, Miami’s best period in all three games so far. The Heat have outscored foes 86-41 in that quarter through the season’s first week. And even though the outcome was decided, Wade, James and Bosh all played some in the fourth — not to send a message, but rather to work on continuity, Spoelstra said.

“It’s a good win,” Spoelstra said, “but we can’t get carried away.”

NOTES: Wade’s girlfriend, Gabrielle Union got a birthday bouquet of flowers in the fourth quarter. … James said before the game that he doesn’t see his high rate of turnovers — he had 17 in the first two games, then just three Friday — as a problem. “I’m still learning my teammates. Teammates are still learning me,” he said. … Celebrities in attendance included Marc Anthony, Chris Brown, Jon Secada and Ludacris. Clarence Clemons performed the national anthem. … The Magic were without PG Jason Williams, suspended after making contact with an official in the final minute of Orlando’s win over Washington.